Outdoor unit of heat pump water heater

ABSTRACT

The present invention provides an outdoor unit of a heat pump water heater that has improved heat dissipation performance of an electrical unit achieved by improving the placement of the electrical unit and a remote controller. A compressor  31  is placed on one side in an exterior case  51 , while an evaporator  32  and an air blower  34  are placed lateral to the compressor. An electrical unit  70  is placed on one side in the exterior case below a top panel  56 , and a remote controller  71  is placed between a side plate  55 B of the exterior case and the electrical unit. A heat dissipation section  72  is provided on a portion of the electrical unit, the portion being positioned on the opposite side from the remote controller, and is positioned within a ventilation path of the air blower.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Stage Patent Application under 37 U.S.C. § 371 of International Patent Application No. PCT/JP2017/018600, filed on May 11, 2017, which claims the benefit of Japanese Patent Application No. JP 2016-106115, filed on May 27, 2016, the disclosures of each of which are incorporated herein by reference in their entirety.

TECHNICAL FIELD

The present invention relates to an outdoor unit of a heat pump water heater adapted to heat water for hot water supply by a heat pump circuit.

BACKGROUND ART

Hitherto, as this type of heat pump water heater, there has been known one that includes a hot water storage tank which stores water for hot water supply, a hot water supply circuit in which the water for hot water supply in the hot water storage tank is taken out from a lower part of the hot water storage tank by a pump, circulated into a water heat exchanger, and led into an upper part of the hot water storage tank, and a heat pump circuit for heating, by a refrigerant, the water for hot water supply, which circulates through the water heat exchanger of the hot water supply circuit (refer to, for example, Patent Document 1). Further, as an outdoor unit of an air conditioner using a heat pump, there has been developed one that has a compressor and a heat exchanger, and a fan, which are placed in parallel in an exterior case, and an electrical unit provided above the compressor. Switches and a display section of the electrical unit are placed corresponding to a hole for a detachable handle (refer to, for example, Patent Document 2).

CITATION LIST Patent Documents Patent Document 1: Japanese Patent Application Publication No. 2010-25493 Patent Document 2: Japanese Patent Application Publication No. 2007-51822 SUMMARY OF THE INVENTION Problems to be Solved by the Invention

The electrical unit has a power element, which generates heat. In the aforesaid conventional outdoor unit, the electrical unit is placed above the compressor, thus making it difficult to air-cool the electrical unit by ventilation using an air blower. In addition, the switches and the display section device are provided at a lower part of the electrical unit, so that the switches and the display section device have to be operated through the hole for the handle, resulting in extremely poor operability.

The present invention has been made to solve the technological difficulties of the conventional art described above, and an object of the invention is to provide an outdoor unit of a heat pump water heater featuring improved heat dissipation performance of an electrical unit achieved by improving the placement of the electrical unit, which has a heat dissipation section, and a remote controller having a display section, and also featuring improved visibility and operability of the remote controller.

Means for Solving the Problems

An outdoor unit of a heat pump water heater in accordance with the present invention has a compressor and an evaporator constituting a heat pump circuit, and an air blower for ventilating the evaporator, which are provided in an exterior case that has side plates and a detachable top panel, the outdoor unit including: an electrical unit, which has a heat dissipation section and which controls the compressor and the air blower; and an operation remote controller, which has a display section and which is connected to the electrical unit, wherein the compressor is placed on one side in the exterior case, the evaporator and the air blower are placed lateral to the compressor, the electrical unit is placed on one side in the exterior case under the top panel, the remote controller is placed between a side plate of the exterior case, the side plate being adjacent to the compressor, and the electrical unit, and the heat dissipation section is provided on a portion of the electrical unit, the portion being on the opposite side from the remote controller, and is positioned within a ventilation path of the air blower.

The outdoor unit of the heat pump water heater according to the present invention of claim 2 includes a retaining section which retains the remote controller between the electrical unit and the side plate, and the remote controller can be taken out of the retaining section in a state in which the top panel has been removed in the aforesaid invention. In the outdoor unit of the heat pump water heater according to the invention of claim 3, the remote controller is retained by the retaining section in a state in which the remote controller is locked to a locking member, and the top panel is in contact with the locking member through the intermediary of a buffer in a state in which the remote controller and the locking member are retained by the retaining section in the aforesaid invention.

In the outdoor unit of the heat pump water heater according to the invention of claim 4, a window hole is formed in the side plate at a position corresponding to the display section of the remote controller in each of the aforesaid inventions.

In the outdoor unit of the heat pump water heater according to the invention of claim 5, a pull-out port is formed in the top panel at a position corresponding to the remote controller, the remote controller can be taken out from the pull-out port, and the pull-out port is openably closed by a cover member in each of the aforesaid inventions.

Advantageous Effect of the Invention

According to the present invention, the outdoor unit of a heat pump water heater has the compressor and the evaporator constituting the heat pump circuit, and the air blower for ventilating the evaporator, which are provided in the exterior case that has the side plates and the detachable top panel. The outdoor unit includes: the electrical unit, which has a heat dissipation section and which controls the compressor and the air blower; and the operation remote controller, which has the display section and which is connected to the electrical unit, wherein the compressor is placed on one side in the exterior case, the evaporator and the air blower are placed lateral to the compressor, the electrical unit is placed on one side in the exterior case under the top panel, the remote controller is placed between the side plate of the exterior case, the side plate being adjacent to the compressor, and the electrical unit, and the heat dissipation section is provided on the portion of the electrical unit, the portion being on the opposite side from the remote controller, and is positioned within a ventilation path of the air blower. Thus, the electrical unit is spaced from the side plate adjacent to the compressor because of the presence of the remote controller, and the heat dissipation section thereof is closer to the air blower.

With this arrangement, the wind from the air blower is blown more strongly to the heat dissipation section of the electrical unit, thus making it possible to markedly improve the heat dissipation performance of the electrical unit. Further, the remote controller can be operated by removing the detachable top panel of the exterior case, thus leading to improved operability for initial setting and maintenance.

In this case, according to the invention described in claim 2, the retaining section that retains the remote controller is provided between the electrical unit and the side plate, and the remote controller can be taken out of the retaining section in the state in which the top panel has been removed, thus leading to significantly improved operability.

Further, according to the invention described in claim 3, the remote controller is retained by the retaining section in the state in which the remote controller is locked to the locking member, and the top panel is in contact with the locking member through the intermediary of the buffer in the state in which the remote controller and the locking member are retained by the retaining section. Hence, the top panel serves also as the member for fixing the remote controller, thus making it possible to prevent the inconvenient vertical vibration of the remote controller and the locking member caused by the vibration during transport without the need for providing any extra members. This enables the number of components to be reduced.

Further, according to the invention described in claim 4, the window hole formed in the side plate at the position corresponding to the display section of the remote controller enables the display section of the remote controller to be visually checked without removing the top panel, leading to significantly improved maintainability. In this case, the window hole is formed in the side plate of the exterior case. This makes it difficult for rain water to accumulate, thus providing the advantage of much greater waterproofing, as compared with the case where the window hole is formed in the top panel.

In addition, according to the invention described in claim 5, the pull-out port is formed in the top panel at the position corresponding to the remote controller such that the remote controller can be taken out of the pull-out port, and the pull-out port is openably closed by the cover member. This arrangement makes it possible to operate the remote controller without detaching the top panel, leading to further improved operability for setting and maintenance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a configuration diagram of a heat pump water heater as an embodiment to which the present invention has been applied;

FIG. 2 is a schematic sectional view illustrating the internal configuration of an outdoor unit of the heat pump water heater of FIG. 1 (First Embodiment);

FIG. 3 is a side view of the outdoor unit of FIG. 2;

FIG. 4 is a front view of a remote controller of the heat pump water heater of FIG. 1;

FIG. 5 is a side view of the remote controller of FIG. 4 and locking members;

FIG. 6 is a perspective view of the remote controller and the locking members of FIG. 5 and a retaining section; and

FIG. 7 is a schematic sectional view illustrating the internal configuration of an outdoor unit of a heat pump water heater of another embodiment according to the present invention (Second Embodiment).

MODE FOR CARRYING OUT THE INVENTION

The following will describe in detail the embodiments of the present invention with reference to the accompanying drawings.

First Embodiment

(1) Heat Pump Water Heater 1

A heat pump water heater 1 according to the present embodiment includes a hot water storage tank 10, which stores water for hot water supply, a hot water supply circuit 20, which circulates the water for hot water supply of the hot water storage tank 10, a heat pump circuit 30, which circulates a refrigerant, and a water heat exchanger 40, which performs heat exchange between the water for hot water supply of the hot water supply circuit 20 and the refrigerant of the heat pump circuit 30. The heat pump water heater 1 is adapted to heat the water for hot water supply circulating through the hot water supply circuit 20 by the refrigerant of the heat pump circuit 30.

(2) Hot Water Storage Tank 10

The hot water storage tank 10 is formed of a vertically long, hermetically sealed vessel, and installed outdoors or the like. A water supply pipe 11 for introducing tap water is connected to a lower part of the hot water storage tank 10. Further, the water supply pipe 11 is provided with a pressure reducing valve 12. A hot water supply pipe 13 for supplying the hot water in the hot water storage tank 10 to a hot water supply destination in a residence is connected to an upper part of the hot water storage tank 10, the hot water supply pipe 13 and the water supply pipe 11 being connected through a bypass pipe 14.

A mixing valve 15 is provided between the hot water supply pipe 13 and the bypass pipe 14. The mixing valve 15 is adapted to mix the hot water in the hot water storage tank 10 and the water from the water supply pipe 11 and to circulate the mixture into the hot water supply pipe 13. Further, the hot water storage tank 10 is provided with a stored hot water temperature sensor 16, which detects the temperature of the water for hot water supply in the hot water storage tank 10. The stored hot water temperature sensor 16 is installed at a predetermined location in the vertical direction of the hot water storage tank 10 (approximately at the center in the embodiment).

(3) Hot Water Supply Circuit 20

The hot water supply circuit 20 includes an inflow pipe 21 connected between a lower part of the hot water storage tank 10 and an inflow-side connection port 52 formed in the outer surface of an exterior case 51 of an outdoor unit 50, which will be discussed later, a water pump 23, an inflow water pipe 22 connected between the inlet side of the water pump 23 and the connection port 52, an outflow water pipe 24 connected between a discharge side of the water pump 23 and the inflow side of the water heat exchanger 40, an outlet pipe 26 connected between the outflow side of the water heat exchanger 40 and an outflow-side connection port 54 installed to the outer surface of the exterior case 51, and an outflow pipe 27 connected to the connection port 54 and an upper part of the hot water storage tank 10. The inflow water pipe 22 is provided with an inflow water temperature sensor 28, which detects the temperature of the water for hot water supply, and the outlet pipe 26 is provided with an outflow hot water temperature sensor 29, which detects the temperature of the water for hot water supply.

The hot water supply circuit 20 is provided with a drain plug 18 for draining the water inside. The drain plug 18 is also provided on the outer surface of the exterior case 51 of the outdoor unit 50 and connected in communication with the inflow water pipe 22 through a drain pipe 19. Reference numerals 52A and 54A denote air vent valves provided at the connection ports 52 and 54, respectively. Reference numeral 25 denotes a filter provided in the inflow water pipe 22.

(4) Heat Pump Circuit 30

The heat pump circuit 30 is composed of a refrigerant circuit formed by connecting a compressor 31, an evaporator 32, an expansion valve (pressure reducing unit) 33, and the water heat exchanger 40, and is configured such that a refrigerant is circulated in the order of the compressor 31, the water heat exchanger 40, the expansion valve 33, the evaporator 32, and the compressor 31. The refrigerant used for the heat pump circuit 30 is a natural refrigerant, such as CO₂ (carbon dioxide). Further, reference numeral 34 denotes an air blower for ventilating the evaporator 32.

The water heat exchanger 40 is composed of a double-pipe heat exchanger, which has a refrigerant circulation passage 41 and a water circulation passage 42. The heat pump circuit 30 is connected to the refrigerant circulation passage 41, and the outflow water pipe 24 and the outlet pipe 26 of the hot water supply circuit 20 are connected to the water circulation passage 42.

The heat pump water heater 1 according to the embodiment includes the outdoor unit 50, in which the water pump 23, the heat pump circuit 30, the water heat exchanger 40, the inflow water temperature sensor 28, the outflow hot water temperature sensor 29 and the like are placed, and a tank unit 60, in which the hot water storage tank 10 and the stored hot water temperature sensor 16 are placed. The outdoor unit 50 and the tank unit 60 are connected at the connection ports 52 and 54 installed to the exterior case 51 of the outdoor unit 50 through the inflow pipe 21 and the outflow pipe 27 of the hot water supply circuit 20. Further, the outdoor unit 50 is installed outdoors or the like and adjacently to the hot water storage tank 10.

(5) Electrical Unit 70

Further, the heat pump water heater 1 is provided with the electrical unit 70, to which the stored hot water temperature sensor 16, the inflow water temperature sensor 28, the outflow hot water temperature sensor 29, the compressor 31, the air blower 34, and the water pump 23 are connected. The electrical unit 70 is placed in the exterior case 51 of the outdoor unit 50.

The electrical unit 70 includes a CPU, which stores programs, and a power element (heat generating element), and the electrical unit 70 according to the embodiment is configured to control the compressor 31, the water pump 23, and the air blower 34 on the basis of the temperatures detected by the stored hot water temperature sensor 16 and the inflow water temperature sensor 28. Further, the electrical unit 70 has a timer function. Connected to the electrical unit 70 is a remote controller (operation panel) 71 for performing operations, including the setting of the timer function, and display section for displaying errors and the like, the remote controller 71 being placed also in the exterior case 51.

When the water pump 23 of the hot water supply circuit 20 is actuated by the electrical unit 70, the water for hot water supply in the hot water storage tank 10 is led out from the lower part of the hot water storage tank 10 and flows in the inflow pipe 21 toward the outdoor unit 50. The water for hot water supply moves up in the inflow pipe 21 and enters into the outdoor unit 50 through the connection port 52 and further passes through the water circulation passage 42 of the water heat exchanger 40 through the intermediary of the inflow water pipe 22, the water pump 23, and the outflow water pipe 24. Thereafter, the water for hot water supply passes through the outlet pipe 26 and reaches the outflow pipe 27 through the connection port 54. The water for hot water supply that has entered into the outflow pipe 27 will flow through the outflow pipe 27 and then flow into the upper part in the hot water storage tank 10.

Further, when the compressor 31 of the heat pump circuit 30 is actuated by the electrical unit 70, a hot refrigerant (carbon dioxide) discharged from the compressor 31 is circulated through the refrigerant circulation passage 41 of the water heat exchanger 40, and the heat exchange is carried out between the hot refrigerant in the refrigerant circulation passage 41 and the water for hot water supply in the water circulation passage 42. Thus, the water for hot water supply of the hot water supply circuit 20 is heated by the water heat exchanger 40. The temperature of the hot refrigerant is decreased by heating the water for hot water supply by the water heat exchanger 40. The refrigerant further passes through the expansion valve 33 so as to expand into a low temperature, low pressure state, thus turning into a gas-liquid two-phase refrigerant. The gas-liquid two-phase refrigerant flows into the evaporator 32 and evaporates. The evaporator 32 is ventilated with outdoor air by the air blower 34, so that the refrigerant draws up heat from the outdoor air by the endothermic action of evaporation. Then, the refrigerant that has absorbed heat in the evaporator 32 repeats the cycle of being drawn into the compressor 31.

Further, when hot water is used at the hot water supply destination, the water for hot water supply at the upper part of the hot water storage tank 10 flows out into the hot water supply pipe 13 and the amount of water that is equal to the amount of the water for hot water supply that has flowed out is supplied to the lower part of the hot water storage tank 10 through the water supply pipe 11. In other words, the use of the hot water causes the high-temperature water for hot water supply in the hot water storage tank 10 to decrease, while the low-temperature water for hot water supply increases at the lower part of the hot water storage tank 10, so that the temperature detected by the stored hot water temperature sensor 16 will gradually decrease.

If the temperature detected by the stored hot water temperature sensor 16 decreases to a predetermined stored hot water temperature or lower, then the electrical unit 70 actuates the compressor 31, the air blower 34, and the water pump 23 to start a boiling operation. Thereafter, when the temperature detected by the inflow water temperature sensor 28 reaches a predetermined inflow water temperature or higher, the boiling operation is terminated. Further, even if the temperature detected by the stored hot water temperature sensor 16 does not decrease to a predetermined stored hot water temperature or lower, the electrical unit 70 actuates the compressor 31, the air blower 34, and the water pump 23 to start the boiling operation when the time measured by the timer function from the end of the previous boiling operation reaches a predetermined time. Thereafter, the boiling operation is terminated when the temperature detected by the inflow water temperature sensor 28 reaches the predetermined inflow water temperature or higher.

The electrical unit 70 carries out the boiling operation for storing water for hot water supply of a predetermined temperature in the hot water storage tank 10 as described above. The stored hot water temperature sensor 16, which detects the temperature of the water for hot water supply in the hot water storage tank 10, is provided at a predetermined vertical location of the hot water storage tank 10, and the stored hot water temperature sensor 16 is connected to the electrical unit 70, so that the electrical unit 70 carries out the boiling operation on the basis of the temperature detected by the stored hot water temperature sensor 16. This eliminates the need for providing the hot water storage tank 10 with an electrical unit. Thus, a general-purpose product can be used as the hot water storage tank 10, contributing to improved versatility.

(6) Internal Configuration of the Outdoor Unit 50

Referring now to FIG. 2 to FIG. 6, the internal configuration of the outdoor unit 50 will be described. The exterior case 51 of the outdoor unit 50 is composed of a main body 55 having left and right side plates 55A and 55B, and a top panel 56 detachably attached to the upper surface of the main body 55 by screws 63. The interior of the main body 55 is divided into left and right compartments by a partition wall 57. As viewed facing the partition wall 57, a first machine compartment 58 is located on the right side (one side) and a second machine compartment 59 is located on the left side (the other side).

The compressor 31 of the heat pump circuit 30 is installed in the first machine compartment 58, and the water heat exchanger 40 is installed on the bottom in the second machine compartment 59. The evaporator 32 of the heat pump circuit 30 is placed on the back side in the second machine compartment 59, and the air blower 34 is placed in front of the evaporator 32 in the second machine compai linent 59. In other words, the compressor 31 is positioned on one side in the exterior case 51, and the evaporator 32 and the air blower 34 are placed lateral to the compressor 31 (on the left, viewed from the front).

A shroud 61 is provided around the air blower 34. The shroud 61 has a circular cylindrical shape, enclosing the air blower 34. Further, the water pump 23 is installed at a corner in the second machine compartment 59 formed by the shroud 61, the partition wall 57, and the water heat exchanger 40, and the exterior of the water pump 23 is covered by a pump cover 62. As described above, the water pump 23 is placed at the corner in the second machine compartment 59 of the exterior case 51, which is formed by the shroud 61, thus enabling the water pump 23 to be installed in the exterior case 51 of the outdoor unit 50 by making use of the wasted space in the second machine compartment 59, which is formed by the shroud 61 of the air blower 34. This enables the outdoor unit 50 to be made smaller.

Further, the drain plug 18 is provided at the lowermost part of the side plate 55B on one side of the main body 55 of the exterior case 51. The position is lower than the water pump 23 installed above the water heat exchanger 40. Thus, the drain plug 18 is placed at the position that is lower than the water pump 23, so that releasing the drain plug 18 causes the water of the water pump 23, which is located above the drain plug 18, to come out. In other words, when the drainage is performed through the inflow water pipe 22 of the hot water supply circuit 20, the water of the water pump 23 can be also drained easily by the drain plug 18, thus enhancing the convenience.

(7) Configurations and Placement of the Electrical Unit 70 and the Remote Controller 71

The electrical unit 70 described above is placed on one side in the exterior case 51 under the top panel 56. In this case, the upper end of the partition wall 57 is spaced from the top panel 56. Further, the electrical unit 70 is placed above the partition wall 57 with an interval provided therebetween, extends from the first machine compartment 58 to the second machine compartment 59, and is also spaced from the side plate 55B on one side. Further, the remote controller 71, which is described above, is placed between the side plate 55B and the electrical unit 70.

Further, the electrical unit 70 is provided with a heat dissipation section 72 (a heat sink composed mainly of aluminum fins), which is installed on the power element for heat exchange. The heat dissipation section 72 is installed to the electrical unit 70 at a portion positioned on the opposite side from the remote controller 71, and is positioned more closely to the center of the air blower 34 by the distance of spacing of the electrical unit 70 from the side plate 55B to place the remote controller 71.

Here, when the air blower 34 is operated as described above, outdoor air is blown onto the evaporator 32. The heat dissipation section 72 is positioned in the ventilation path of the air blower 34. Hence, as the heat dissipation section 72 is closer to the air blower 34, more wind sent from the air blower 34 passes through the heat dissipation section 72, thus achieving satisfactory heat dissipation from the electric components (a CPU and a power element) of the electrical unit 70.

Meanwhile, the remote controller 71 has a display section 73 for displaying errors and the like and switches 74 for performing setting operations and the like, as illustrated in FIG. 4, and is connected to the electrical unit 70 by a cable 76. The remote controller 71 has locking hooks 77 on the back surface thereof, and the remote controller 71 is locked onto a locking member 78 by the locking hooks 77 engaging with the locking member 78, as illustrated in FIG. 5. Further, a buffer 79 composed of a cushion material is attached to the upper end of the locking member 78.

On the other hand, a retaining section 81 is formed on the inner surface of the side plate 55B of the exterior case 51. The retaining section 81 is shaped like a slot that opens to the side plate 55B and also upward, and the remote controller 71 locked to the locking member 78 is held in the retaining section 81 such that the remote controller 71 can be taken out upward. In this case, the remote controller 71 is retained, with the display section 73 being adjacent to the side plate 55B. Further, a see-through window hole 82 is formed in the side plate 55B at the position corresponding to the display section 73, thus making it possible to check from outside an error or the like shown on the display section 73 of the remote controller 71 through the window hole 82. A transparent plate is fitted in the window hole 82 to provide sealing so as to prevent rain water or the like from entering into the window hole 82.

To operate the remote controller 71, the top panel 56 is removed, and the remote controller 71 is pulled out together with the locking member 78 upward from the retaining section 81. The cable 76 is sufficiently long to allow the pull-out operation. After operating the remote controller 71, the remote controller 71 is inserted back into the retaining section 81 to be retained, and the top panel 56 is attached to the main body 55. At this time, the top panel 56 is in contact with the locking member 78 through the intermediary of the buffer 79, thus preventing the remote controller 71 and the locking member 78 from moving.

As described above in detail, in the outdoor unit 50, in which the compressor 31 is placed on one side in the exterior case 51, and the evaporator 32 and the air blower 34 are placed lateral to the compressor 31, the electrical unit 70 is placed on one side in the exterior case 51 under the detachable top panel 56, the remote controller 71 is placed between the side plate 55B adjacent to the compressor 31 (one side) of the exterior case 51 and the electrical unit 70, and the heat dissipation section 72 is provided on the portion of the electrical unit 70, the portion being positioned on the opposite side from the remote controller 71, so that the heat dissipation section 72 is positioned in the ventilation path of the air blower 34. Hence, the presence of the remote controller 71 causes the electrical unit 70 to be spaced from the side plate 55B adjacent to the compressor 31, so that the heat dissipation section 72 is closer to the air blower 34.

Thus, the wind from the air blower 34 is blown more strongly onto the heat dissipation section 72 of the electrical unit 70, enabling significantly improved heat dissipation performance of the electrical unit 70. In addition, the remote controller 71 can be operated by removing the detachable top panel 56 of the exterior case 51, thus leading to improved operability for initial setting and maintenance.

In this case, the retaining section 81, which retains the remote controller 71, is provided between the electrical unit 70 and the side plate 55B, and the remote controller 71 can be taken out of the retaining section 81, with the top panel 56 being removed, so that the operability is significantly improved. In addition, the remote controller 71 is retained by the retaining section 81 in the state in which the remote controller 71 is locked to the locking member 78, and the top panel 56 is in contact with the locking member 78 through the intermediary of the buffer 79 in the state in which the remote controller 71 and the locking member 78 are held by the retaining section 81. Hence, the top panel 56 serves also as the member for fixing the remote controller 71, thus making it possible to prevent the inconvenient vertical vibration of the remote controller 71 and the locking member 78 caused by the vibration during transport without the need for providing any extra members. This enables the number of components to be reduced.

Further, the window hole 82 is formed in the side plate 55B at the position corresponding to the display section 73 of the remote controller 71, so that the display section 73 of the remote controller 71 can be visually checked without removing the top panel 56, leading to significantly improved maintainability. In this case, the window hole 82 is formed in the side plate 55B of the exterior case 51. This makes it difficult for rain water to accumulate, thus providing the advantage of much greater waterproofing, as compared with the case where the window hole is formed in the top panel 56.

Second Embodiment

Next, FIG. 7 is a diagram illustrating the internal configuration of an outdoor unit 50 according to another embodiment. In the drawing, the components denoted by the same reference numerals as those in FIG. 2 will have the same or similar functions. In this embodiment, a pull-out port 83 is formed in one end of a top panel 56. The pull-out port 83 is located immediately above a remote controller 71 and a locking member 78, which are held by a retaining section 81, and has opening dimensions that enable the remote controller 71 and the locking member 78 to be taken out. Further, the pull-out port 83 is openably closed by a cover member 84 pivotably attached to the top panel 56 by a hinge 86.

Further, in this case also, a buffer 79 of the locking member 78 is in contact with the cover member 84. Thus, the pull-out port 83 is formed in the top panel 56 at the position corresponding to the remote controller 71, the remote controller 71 and the locking member 78 can be taken out from the pull-out port 83, and the pull-out port 83 is openably closed by the cover member 84. This arrangement makes it possible to operate the remote controller 71 without detaching the top panel 56, thus leading to further improved operability for setting and maintenance.

The above has described preferred embodiments of the present invention. However, the present invention is not limited to the foregoing embodiments, and various other changes and modifications can be made on the basis of the technical concept of the present invention.

DESCRIPTION OF REFERENCE NUMERALS

-   -   1 heat pump water heater     -   10 hot water storage tank     -   16 stored hot water temperature sensor     -   20 hot water supply circuit     -   22 inflow water pipe     -   23 water pump     -   30 heat pump circuit     -   31 compressor     -   32 evaporator     -   33 expansion valve     -   34 air blower     -   40 water heat exchanger     -   50 outdoor unit     -   51 exterior case     -   55B side plate     -   56 top panel     -   70 electrical unit     -   71 remote controller     -   72 heat dissipation section     -   73 display section     -   78 locking member     -   79 buffer     -   81 retaining section     -   82 window hole     -   83 pull-out port     -   84 cover member 

1. An outdoor unit of a heat pump water heater having a compressor and an evaporator constituting a heat pump circuit, and an air blower for ventilating the evaporator, which are provided in an exterior case which has side plates and a detachable top panel, the outdoor unit comprising: an electrical unit which has a heat dissipation section and which controls the compressor and the air blower; and an operation remote controller which has a display section and which is connected to the electrical unit, wherein the compressor is placed on one side in the exterior case, and the evaporator and the air blower are placed lateral to the compressor, the electrical unit is placed on one side in the exterior case under the top panel, the remote controller is placed between a side plate of the exterior case, the side plate being adjacent to the compressor, and the electrical unit, and the heat dissipation section is provided on a portion of the electrical unit, the portion being positioned on the opposite side from the remote controller, and is positioned within a ventilation path of the air blower.
 2. The outdoor unit of a heat pump water heater according to claim 1, comprising: a retaining section which retains the remote controller between the electrical unit and the side plate, wherein the remote controller can be taken out of the retaining section in a state in which the top panel has been removed.
 3. The outdoor unit of a heat pump water heater according to claim 2, wherein the remote controller is retained by the retaining section in a state in which the remote controller is locked to a locking member, and the top panel is in contact with the locking member through the intermediary of a buffer in a state in which the remote controller and the locking member are retained by the retaining section.
 4. The outdoor unit of a heat pump water heater according to claim 1, wherein a window hole is formed in the side plate at a position corresponding to the display section of the remote controller.
 5. The outdoor unit of a heat pump water heater according to claim 1, wherein a pull-out port is formed in the top panel at a position corresponding to the remote controller to enable the remote controller to be taken out from the pull-out port, and the pull-out port is openably closed by a cover member. 